The endless fascination of right typical atrial flutter: can we predict
The chance for the development of right AFL is strictly related to
changes in functional conduction properties of the atrial myocardium
which are greatly influenced by fibrotic/scar tissue and increased
atrial volume. If these circumstances take place, reduction in
conduction velocity can favor a macro-reentry circuit with the wavefront
that does not meet its refractory tail and perpetuate the arrhythmia.
Therefore, the time required to traverse the entire circuit is related
to the circuit’s functional properties. With pacing from the coronary
sinus os the right atrial collision time (RACT) of the two wavefronts
traveling the circuit in counterclockwise and clockwise direction is
calculated. in this prospective study, a cut-off of 115.5 ms of RACT
showed a sensitivity and specificity of 92.7% and 93.0% respectively
for diagnosis of AFL and an ROC curve indicated an AUC of 0.96 (95% CI:
0.93-1.0, p<0.01). Based on these premises, RACT could be
utilized as new marker for the propensity of developing typical AFL.